Potential for cost economies in guiding therapy in patients with metastatic breast cancer.

Therapeutic response in patients with advanced breast cancer is conventionally assessed with reference to criteria devised by the International Union Against Cancer. Evidence to date suggests, however, that assessments of equivalent quality may be obtained at lower cost from the use of serum markers. The paper presents estimates of potential cost savings resulting from the use of serum markers in place of conventional assessment and argues that the size of these savings merits the establishment of a randomised controlled trial.